Building a treehouse in Ficus, Banyan, or Gumbo Trees

We recently were asked whether it was okay to build a treehouse in a Ficus or Gumbo Tree, which are relatively common across South Florida. While it is well known that palm trees are not safe for building treehouses in, some other unique trees that grow differently warrant special considerations. So without further ado, let’s talk about Gumbo Limbo and Strangler Fig and their suitability for treehouse construction!

The Gumbo Limbo

The Gumbo Limbo, or Bursera Simaruba is fast growing and wind stable. While the trunks often branch into 2-4+ leaders, the multiple trunks are resistant to high winds and they grow thick enough for TAB-supported treehouse attachment systems to work well. The wood is soft and weak, however, so the load ratings per bolt will be on the lower end of the range. If that is a problem, the design can be modified to use more bolts, or upgraded to a larger TAB collar or the addition of struts or suspenders in order to compensate for the difference in wood hardness. As with any tree, but specifically based on this tree’s growth patterns, inspect the unions of the leaders to ensure that the stems are not co-dominant. Many of these tree trunks grow in angling and turning fashion, which can create stress raisers (weak spots of concentrated loads), and can interrupt a typical axial loading engineering scenario. The overall size is small, typically maxing out at 40-60 feet tall, which means that it is likely more suitable for small to medium-sized treehouses. Read more about Gumbo Limbo trees 

The Strangler Fig 

The Strangler Fig, or Ficus Aurea is a much more challenging species to work with. The way they grow, by crawling up other trees and surrounding them and dropping vines back down to the earth, creates a totally unique structure that might require a degree in bio-mechanical engineering to fully assess. The wood tissue itself is fast-growing and soft, so lower load ratings per bolt apply here, too. Also, the fast growth rate will make it grow over attachments quickly. Other issues:

1. If it grows dependent on a host plant, then the host plant dies and decays, then the tree may become unstable.
2. Ficus has a variety of “trunks” of intertwining strands, making it tough to use except where single trunks become large enough.
3. The way that strands of tree tissues fuse is unpredictable, possibly creating invisible weak spots in the wood. Be careful to choose a solid, reliable attachment point. Inspect the wood chips as you pre-drill to look for irregularities or decay.

Overall, be more careful with the Ficus family in Florida, which includes many species including Banyans. Sometimes TAB systems may be appropriate, but other times you may lean toward other treehouse building solutions such as more smaller attachments or just switch to ground support. Read more about Ficus Aurea trees